diff --git a/library/include/mobilisis/calculator_functions.h b/library/include/mobilisis/calculator_functions.h
index da87279..eed0d0d 100644
--- a/library/include/mobilisis/calculator_functions.h
+++ b/library/include/mobilisis/calculator_functions.h
@@ -45,6 +45,20 @@ public:
     // (e.g. Schoenau/Koenigsee)
     //
     QList<int> GetTimeSteps(Configuration *cfg) const;
+    QList<int> GetSteps(Configuration *cfg) const { return GetTimeSteps(cfg); }
+
+    // additional helper functions
+    bool noSpecialDays(Configuration const *cfg) const {
+        return (cfg->SpecialDays.size() == 0) && (cfg->SpecialDaysWorktime.size() == 0);
+    }
+    bool specialDays(Configuration const *cfg) const {
+        return !noSpecialDays(cfg);
+    }
+    bool tariffIs24_7(Configuration const *cfg) const {
+        return (cfg->YearPeriod.size() == 0 &&
+                cfg->SpecialDays.size() == 0 &&
+                cfg->SpecialDaysWorktime.size() == 0);
+    }
 
 private:
     // Introduced for PaymentMethod::Steps (e.g. Schoenau)